Thursday, April 18, 2013

Hammerhead worm (Bipalium rauchi) in Bukit Brown

In my many trips to Bukit Brown, i have seen many birds, butterflies, mammals and reptiles. In recent trips, i been noticing this unique looking worm. It's called the Hammerhead worm or slug (Bipalium kewense). [April 20, 20013, article afternote: i wrongly identified it based on expert comment from reader Pat, its actually Diversibipalium rauchi (synonym: Bipalium rauchi)].

The key take away i learnt from this is that a mature woodland place like Bukit Brown is able to support such native land planarians more commonly found in heavily forested areas.

At Hill 3 (on the path to Ong Sam Leong)
January 12, 2013

At Hill 4 Block A
April 14, 2013
Bukit Brown plays host to a rich habitat of flora and fauna and plays host to many forest and woodland
trees and wildlife. Birds, do see my post on birds. Reptiles that i seen so far include seen the spitting cobra, the resident clouded monitor lizard (varanus nebulosus) and the mammals i seen include the Lesser Dog-faced Fruit Bat also known as the Common Fruit Bat (Cynopterus brachyotis ) that roost at the bird nest ferns on the rain trees at the roundabout.
Clouded monitor up a Tembusu Tree


Clarification from reader Pat. (Many thanks for sharing and clarifying!)
The specimens (head: orange-white with black mid-stripe, body: multiple black & white lateral bands on dorsal side) as shown in your 2 photos appear to be Diversibipalium rauchi (Graff, 1898) (synonym: Bipalium rauchi) instead.

Diversibipalium rauchi is a terrestrial planarian (non-parasitic flatworm related to marine flatworms) that was first taxonomically described from Singapore in 1898 by Austrian zoologist Ludwig von Graff. Besides Peninsular Malaysia, this species is also periodically sighted in S'pore's forests. It's reported from Florida as well, probably introduced there via the horticultural trade.

Thanks for sharing your sightings at Bukit Brown. It shows that the mature woodland there is moist enough to support native land planarians.

Some photos for reference:
* Specimen from SG (budak - 17 Aug 07)
* Unknown Striped Flatworm from Singapore is probably Bipalium rauchi (What's That Bug - 27 Jul 08)
* Specimen from Venus Drive (S'pore Nature - 20 Nov 09)
* Another Photo (Terrestrial Planaria Flatworms)

Taxonomic info:
* WoRMS Database
* Turbellarian Taxonomic Database
* GBIF Database

Note that the much more cosmopolitan Bipalium kewense (Moseley, 1878) has a very different appearance. Head: pale brownish-purple; Body: 5 thin longitudinal brown dorsal stripes, 2 longitudinal ventral stripes. Natively distributed in Vietnam & Cambodia (& possibly extending to Peninsular Malaysia), this species has been widely introduced across the world, esp. after WWII.

Some photos & info for reference:
* Bipalium kewense (Terrestrial Planaria Flatworms)
* Land Planarians of Taiwan, 特有生物 7(2):23-40, 2005 -- photo (pg 29, fig. 1A), description (pg 31)
* Land Planarian Papers Published in the SHIBUKITSUBO (1998-2001) -- B = Bipalium kewense (Line drawing of dorsal & ventral stripes).


Hammerheard worm (Bipalium Kewense)
Reading more about it i found out it is neither worm nor slug but a flatworm. It belongs to a predatory species that feeds on earthworms. (not very good if you are a farmer). However it is also known to feed on snails and slugs as well.

This species is native to Southeast Asia and thrives on areas with high humidity and as a lot of rain. They are usually found in cool, dark, moist areas (sounds like some areas in Bukit Brown to me). It has however spread to many other countries via greenhouse pots and are deemed as an invasive species. The name ‘kewense’ is because of its discovery at Kew Gardens, London, in 1878.



3 comments:

Pat said...

From post: "It's called the Hammerhead worm or slug (Bipalium kewense)."

The specimens (head: orange-white with black mid-stripe, body: multiple black & white lateral bands on dorsal side) as shown in your 2 photos appear to be Diversibipalium rauchi (Graff, 1898) (synonym: Bipalium rauchi) instead.

Diversibipalium rauchi is a terrestrial planarian (non-parasitic flatworm related to marine flatworms) that was first taxonomically described from Singapore in 1898 by Austrian zoologist Ludwig von Graff. Besides Peninsular Malaysia, this species is also periodically sighted in S'pore's forests. It's reported from Florida as well, probably introduced there via the horticultural trade.

Thanks for sharing your sightings at Bukit Brown. It shows that the mature woodland there is moist enough to support native land planarians.

Some photos for reference:
* Specimen from SG (budak - 17 Aug 07)
* Unknown Striped Flatworm from Singapore is probably Bipalium rauchi (What's That Bug - 27 Jul 08)
* Specimen from Venus Drive (S'pore Nature - 20 Nov 09)
* Another Photo (Terrestrial Planaria Flatworms)

Taxonomic info:
* WoRMS Database
* Turbellarian Taxonomic Database
* GBIF Database


Note that the much more cosmopolitan Bipalium kewense (Moseley, 1878) has a very different appearance. Head: pale brownish-purple; Body: 5 thin longitudinal brown dorsal stripes, 2 longitudinal ventral stripes. Natively distributed in Vietnam & Cambodia (& possibly extending to Peninsular Malaysia), this species has been widely introduced across the world, esp. after WWII.

Some photos & info for reference:
* Bipalium kewense (Terrestrial Planaria Flatworms)
* Land Planarians of Taiwan, 特有生物 7(2):23-40, 2005 -- photo (pg 29, fig. 1A), description (pg 31)
* Land Planarian Papers Published in the SHIBUKITSUBO (1998-2001) -- B = Bipalium kewense (Line drawing of dorsal & ventral stripes)

Rojak Librarian said...

Thanks Pat !!

Pat said...

Hi Peter -- Glad to know about your sightings (biological, historical & otherwise). Your above post also mentions Bukit Brown's resident Clouded Monitor (Varanus nebulosus). This native species also prefers rainforests & adjacent mature woodland. Therefore on mainland S'pore, it is typically spotted around Bukit Timah Nature Reserve, Bukit Batok Nature Park, Central Catchment forest & of course, Bukit Brown.

As for land planarians, they require a highly-humid environment in order to survive. Their (bad-tasting) body mucus is not just a self-defence mechanism, but also an adaptation to maximize moisture retention. A loss of >45% body moisture would quickly result in severe dessication & death. They are also sensitive to heat & direct sunlight.

As such, land planarians are generally found at dark, cool & damp sites such as under logs & leaf litter, or within moist (but not waterlogged) soils. Sometimes (esp. after heavy rains), land planarians can also be observed navigating on damp ground/ above-ground surfaces & on wet plants -- this is usually to seek out prey (eg. earthworms which also tend to emerge from waterlogged soils after rain).

(The closely-related freshwater planarians can survive being submerged, & are typically found in freshwater ponds, streams, lakes & wetlands that relatively free from pollution.)

More info on land planarian (Clemnson University Fact Sheets).


Just a quick note about zoological nomenclature ... by scientific convention, the latin/latinized parts of zoological names [genus epithet, species epithet & subspecies epithet (if any)] are italicized (when typed out) or underlined (when written by hand). Thus, Diversibipalium rauchi. In general literature, it is optional to indicate the name authority (Graff, for the above example), which in turn is not italicized.

For more details:
* Guidelines on Biological Nomenclature (environment.gov.au)
* How to Write Scientific Names of Organisms (Assumption University)
* Binomial Nomenclature (Wikipedia)

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